meta-gplv2

This layer contains a set of recipes corresponding to old, obsolete versions of
software that are GPLv2 licensed where the upstreams have moved to GPLv3 licenses.
These were part of OE-Core until it was realised they are a ticking timebomb
with regard to security updates and general maintenance. By splitting into a separate
layer, it's hoped people realise these may not be the best solution to the
"no GPLv3 problem" and it should also make it clear there is a different quality of
service applied to these recipes.
For now, they do continue to get minimal testing by the Yocto Project but this will
eventually be stopped, with anyone wanting to use them taking up the maintainership.